Vehicle seat

ABSTRACT

A vehicle seat includes a side frame, a cushion panel, and an insertion member. One of the side frame and the cushion panel is provided with an elastically deformed portion including an outer circumferential surface and an inner circumferential surface, the outer circumferential surface being configured to be expanded outward by insertion of the insertion member on the inner side of the inner circumferential surface. The other of the side frame and the cushion panel is provided with a recess forming portion facing the outer circumferential surface of the elastically deformed portion, the recess forming portion having an inner surface configured to be brought into pressure contact with the outer circumferential surface expanded by insertion of the insertion member.

This nonprovisional application is based on Japanese Patent ApplicationNo. 2017-104968 filed on May 26, 2017 with the Japan Patent Office, theentire contents of which are hereby incorporated by reference.

BACKGROUND Field

The present disclosure relates to a vehicle seat.

Description of the Background Art

A technique of joining a plurality of members together by welding isknown for assembling various members such as a frame provided inside avehicle seat and constituting its framework, as disclosed in JapanesePatent Laying-Open No. 2015-003645.

SUMMARY

When joining a plurality of members together by welding, it is difficultto improve the productivity in a step of joining the members together.Separate equipment for the welding is needed, and a processing cost forthe welding is also needed. It is preferable to join various memberssuch as a frame constituting the framework of a vehicle seat whileavoiding the use of a welding process as much as possible.

An object of the present specification is to disclose a vehicle seathaving a configuration that allows a plurality of members constituting aframework of the vehicle seat to be joined together without using awelding process.

A vehicle seat based on one aspect of the present disclosure includes:first and second side frames arranged at a distance from each other in awidth direction; a cushion panel arranged between the first and secondside frames; and an insertion member for fixing the cushion panel to thefirst side frame, one of the first side frame and the cushion panelbeing provided with an elastically deformed portion, the elasticallydeformed portion being formed to extend in the width direction andincluding an outer circumferential surface and an inner circumferentialsurface, the outer circumferential surface being configured to beexpanded outward by insertion of the insertion member on the inner sideof the inner circumferential surface, the other of the first side frameand the cushion panel not provided with the elastically deformed portionbeing provided with a recess forming portion, the recess forming portionbeing formed to extend in the width direction and facing the outercircumferential surface of the elastically deformed portion, the recessforming portion having an inner surface configured to be brought intopressure contact with the outer circumferential surface expanded byinsertion of the insertion member.

A vehicle seat based on another aspect of the present disclosureincludes: a pair of side frames arranged at a distance from each otherin a width direction and each including a front frame portion and a rearframe portion; a cushion panel arranged between the pair of side frames;and an insertion member for fixing the front frame portion and the rearframe portion together, one of the front frame portion and the rearframe portion being provided with an elastically deformed portion, theelastically deformed portion being formed to extend in the widthdirection and including an outer circumferential surface and an innercircumferential surface, the outer circumferential surface beingconfigured to be expanded outward by insertion of the insertion memberon the inner side of the inner circumferential surface, the other of thefront frame portion and the rear frame portion being provided with arecess forming portion, the recess forming portion being formed toextend in the width direction and facing the outer circumferentialsurface of the elastically deformed portion, the recess forming portionhaving an inner surface configured to be brought into pressure contactwith the outer circumferential surface expanded by insertion of theinsertion member.

The foregoing and other objects, features, aspects and advantagesdisclosed in the present specification will become more apparent fromthe following detailed description when taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view showing a general configuration of a vehicle seat1.

FIG. 2 is a side view showing a side frame 10L and a cushion panel 40.

FIG. 3 is a plan view showing side frames 10L, 10R and cushion panel 40.

FIG. 4 is a perspective view showing a mode of external appearance ofside frames 10L, 10R and cushion panel 40 visually recognized as seenfrom the front of a diagonal upper left corner.

FIG. 5 is a perspective view showing a mode of external appearance ofside frames 10L, 10R and cushion panel 40 visually recognized as seenfrom the rear of the diagonal upper left corner.

FIG. 6 is a perspective view showing a mode of external appearance ofside frames 10L, 10R and cushion panel 40 visually recognized as seenfrom the front of a diagonal lower left corner.

FIG. 7 is a perspective view showing a front frame portion 20 providedon side frame 10L and a front panel portion 50 provided on cushion panel40 in a separated state.

FIG. 8 is a side view showing front frame portion 20 provided on sideframe 10L and front panel portion 50 provided on cushion panel 40 in anassembled state.

FIG. 9 is a perspective view showing front frame portion 20 and a rearframe portion 30 provided on side frame 10L in a separated state.

FIG. 10 is a side view showing front frame portion 20 and rear frameportion 30 provided on side frame 10L in an assembled state.

FIG. 11 is a perspective view showing rear frame portion 30 provided onside frame 10L and a rear panel portion 60 provided on cushion panel 40in a separated state.

FIG. 12 is a side view showing rear frame portion 30 provided on sideframe 10L and rear panel portion 60 provided on cushion panel 40 in anassembled state.

FIG. 13 is a side view illustrating a function and effect of vehicleseat 1 in an embodiment.

FIG. 14 is a side view regarding a vehicle seat in a variation of theembodiment, which shows front frame portion 20 and rear frame portion 30provided on side frame 10L in an assembled state in this variation.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

An embodiment will be described hereinafter with reference to thedrawings. The same and corresponding components are designated by thesame reference numerals and redundant description may not be repeated.

Vehicle Seat 1

FIG. 1 is a side view showing a general configuration of a vehicle seat1. Vehicle seat 1 is configured as a back seat of an automobile, forexample. Vehicle seat 1 has a seat back 2 serving as a backrest portionof a seated passenger, a seat cushion 3 serving as a sitting portion,and a base 4 to support these seat back 2 and seat cushion 3 withrespect to a floor of the vehicle.

Lower end portions on the right and left sides of seat back 2 arecoupled to rear end portions on the right and left sides of base 4through a recliner (not shown), respectively. A backrest angle of seatback 2 is held in a fixed state under normal conditions. The fixed stateof the backrest angle of seat back 2 is released by operation of atip-up lever (not shown) provided on an outer portion of base 4. Seatback 2 is biased such that it is folded forward to a position where itassumes a forward leaning posture and held there.

A hinge shaft 5 having an axial direction oriented at a directionparallel to the width direction (the right to left direction of vehicleseat 1) is provided inside seat cushion 3. Rear portions on the rightand left sides of seat cushion 3 are rotatably coupled to rear portionson the right and left sides of base 4 through hinge shaft 5,respectively. Seat cushion 3 is coupled to base 4 through a tip-upmechanism (not shown). Under normal conditions, seat cushion 3 is fixedin a state of the seating position where it is collapsed on base 4(cushion rubber 4A), and held in the state that allows the seatedpassenger to sit on the upper side of seat cushion 3.

The fixed state of seat cushion 3 at the seating position with respectto base 4 is released by operation of the tip-up lever (not shown). Seatcushion 3 is biased such that it is tipped up rearward to apredetermined tipped-up position around hinge shaft 5 and held there. Asa result of this tip-up operation, seat cushion 3 and seat back 2 thathas been folded forward to the forward leaning position are brought intoa state where they are stacked on each other in the front to reardirection of the seat.

By simultaneously performing the operation of folding seat back 2forward and the operation of tipping up seat cushion 3 rearward, seatback 2 and seat cushion 3 are brought into a state where they arecompactly folded on each other in the front to rear direction of theseat. Slide rails (not shown) are provided between base 4 and the floorof the vehicle. By sliding the entire vehicle seat 1 forward by theslide rails after the tip-up operation, the space where vehicle seat 1was installed is turned into a space which opens widely rearward.

Provided inside seat cushion 3 operated as described above are a pair ofside frames (side frames 10L and 10R) and a cushion panel (cushion panel40) as framework members of seat cushion 3. As will be described laterin detail, each of side frames 10L and 10R includes a front frameportion 20 and a rear frame portion 30 (see FIGS. 3 to 6 and the like).Cushion panel 40 includes a front panel portion 50 and a rear panelportion 60 (see FIGS. 3 to 6 and the like). These features will now bedescribed.

FIG. 2 is a side view showing side frame 10L and cushion panel 40. FIG.3 is a plan view showing side frames 10L, 10R and cushion panel 40. FIG.4 is a perspective view showing a mode of external appearance of sideframes 10L, 10R and cushion panel 40 visually recognized as seen fromthe front of a diagonal upper left corner. FIG. 5 is a perspective viewshowing a mode of external appearance of side frames 10L, 10R andcushion panel 40 visually recognized as seen from the rear of thediagonal upper left corner. FIG. 6 is a perspective view showing a modeof external appearance of side frames 10L, 10R and cushion panel 40visually recognized as seen from the front of a diagonal lower leftcorner.

Referring to FIGS. 2 to 6, vehicle seat 1 (FIG. 1) has the pair of sideframes 10L and 10R (FIG. 3) arranged at a distance from each other inthe width direction (the right to left direction of vehicle seat 1),cushion panel 40 arranged between the pair of side frames 10L and 10R,and screws 70LA, 70LB, 70LC, 70RA, 70RB, 70RC (FIG. 3) as insertionmembers for fixing cushion panel 40 to the pair of side frames 10L and10R. For the convenience of illustration, screws 70LA, 70LB, 70LC, 70RA,70RB and 70RC (see FIG. 7) are not depicted in FIGS. 4 to 6 as well asFIG. 13 and the like which will be described later.

Side Frames 10L and 10R

Each of side frames 10L and 10R includes front frame portion 20 and rearframe portion 30. Front frame portion 20 provided on side frame 10L andfront frame portion 20 provided on side frame 10R have the sameconfiguration. Rear frame portion 30 provided on side frame 10L and rearframe portion 30 provided on side frame 10R have the same configuration.FIG. 7 is a perspective view showing front frame portion 20 provided onside frame 10L and front panel portion 50 provided on cushion panel 40in a separated state.

Front Frame Portion 20

Referring mainly to FIGS. 2 and 7, front frame portion 20 has a frontend portion 21, an upper flat plate portion 22, lower flat plateportions 23A, 23B, a suspended portion 24A, a connecting portion 24B, anelastically deformed portion 25, recess forming portions 26, 27, a rearupper fitting portion 28, and a rear lower fitting portion 29. Each ofthem is formed to extend in the width direction (a direction of an arrowAR shown in FIG. 7) of vehicle seat 1 (FIG. 1). Front frame portion 20is fabricated by being cut from an extrusion material made of analuminum alloy or a magnesium alloy having a constant cross-sectionalshape in a direction orthogonal to the width direction.

Front end portion 21 has the shape of a curved plate curved in asemi-circular arc. Upper flat plate portion 22 is continuous with anupper portion of front end portion 21, and extends in the form of a flatplate from the upper portion of front end portion 21 toward the positionof rear upper fitting portion 28. Lower flat plate portion 23A iscontinuous with a lower portion of front end portion 21. Lower flatplate portion 23A extends such that the spacing in a height directionbetween lower flat plate portion 23A and upper flat plate portion 22gradually increases from the front side to the rear side. Lower flatplate portion 23B is continuous with the rear end of lower flat plateportion 23A, and extends in the form of a flat plate from the rear endof lower flat plate portion 23A toward the position of rear lowerfitting portion 29.

Suspended portion 24A is provided to hang down from a portion of upperflat plate portion 22 located between front end portion 21 and rearupper fitting portion 28 toward lower flat plate portion 23A. Suspendedportion 24A extends in the form of a flat plate from this portion for alength that does not reach lower flat plate portion 23A, and extends ina direction generally orthogonal to lower flat plate portion 23A.

Connecting portion 24B has the shape of a flat plate, and connects aportion located between lower flat plate portion 23A and lower flatplate portion 23B, and a portion of upper flat plate portion 22 inproximity to rear upper fitting portion 28. Front end portion 21, upperflat plate portion 22, connecting portion 24B, and lower flat plateportion 23A assume a continuous and closed annular shape (frame shape)as a whole. FIG. 8 is a side view showing front frame portion 20provided on side frame 10L and front panel portion 50 provided oncushion panel 40 in an assembled state.

Elastically Deformed Portion 25

As shown in FIGS. 7 and 8, elastically deformed portion 25 is providedat the lower end of suspended portion 24A. Elastically deformed portion25 is also formed to extend in the width direction (the direction ofarrow AR). Elastically deformed portion 25 includes an outercircumferential surface located in front of suspended portion 24A (afront end 25F of the outer circumferential surface), an outercircumferential surface located behind suspended portion 24A (a rear end25B of the outer circumferential surface), and an inner circumferentialsurface 25S located opposite to suspended portion 24A (on the lower flatplate portion 23A side).

Inner circumferential surface 25S has a substantially C-shapedcross-sectional shape, and opens toward lower flat plate portion 23A(FIG. 7). The front side of inner circumferential surface 25S isprovided with a forwardly extending first piece portion 25FT. An endface of first piece portion 25FT in the forwardly extending directionforms front end 25F. Front end 25F is part of the outer circumferentialsurface of elastically deformed portion 25. The rear side of innercircumferential surface 25S is provided with a rearwardly extendingsecond piece portion 25BT. An end face of second piece portion 25BT inthe rearwardly extending direction forms rear end 25B. Rear end 25B ispart of the outer circumferential surface of elastically deformedportion 25.

Recess Forming Portions 26 and 27

Recess forming portion 26 has the shape of a curved plate extending todescribe a semi-circular arc forward, while extending upward from lowerflat plate portion 23A toward upper flat plate portion 22. Recessforming portion 26 is also formed to extend in the width direction (thedirection of arrow AR). Recess forming portion 26 includes an innersurface 26S, with a forwardly projecting protrusion 26U being formed oninner surface 26S.

Recess forming portion 27 includes curved portions 27A and 27B extendingin the width direction (the direction of arrow AR). Curved portions 27Aand 27B face each other, and extend such that each describes asemi-circular arc forward from connecting portion 24B. Recess formingportion 27 includes inner surfaces 27AS and 27BS, with a forwardlyprojecting protrusion 27U being formed between inner surfaces 27AS and27BS.

Rear Upper Fitting Portion 28 and Rear Lower Fitting Portion 29

FIG. 9 is a perspective view showing front frame portion 20 and rearframe portion 30 provided on side frame 10L in a separated state. FIG.10 is a side view showing front frame portion 20 and rear frame portion30 provided on side frame 10L in an assembled state. As shown in FIGS. 9and 10, rear upper fitting portion 28 is formed at a rear portion ofupper flat plate portion 22 (front frame portion 20), and rear lowerfitting portion 29 is formed at a rear portion of lower flat plateportion 23B (front frame portion 20).

Rear upper fitting portion 28 has a protruding shape extending downwardfrom above in the above-described state of the seating position (thestate shown in FIG. 1). Rear upper fitting portion 28 is provided with arear upper inclined surface 28T extending obliquely downward and forwardin the above-described state of the seating position. Rear upperinclined surface 28T is formed by a forwardly facing portion of asurface of rear upper fitting portion 28.

Rear lower fitting portion 29 has a protruding shape extending upwardfrom below in the above-described state of the seating position (thestate shown in FIG. 1). Rear lower fitting portion 29 is provided with arear lower inclined surface 29T extending obliquely upward and rearwardin the above-described state of the seating position. Rear lowerinclined surface 29T is formed by a forwardly facing portion of asurface of rear lower fitting portion 29.

Rear Frame Portion 30

FIG. 11 is a perspective view showing rear frame portion 30 provided onside frame 10L and rear panel portion 60 provided on cushion panel 40 ina separated state. FIG. 12 is a side view showing rear frame portion 30provided on side frame 10L and rear panel portion 60 provided on cushionpanel 40 in an assembled state.

Referring mainly to FIGS. 2, 11 and 12, rear frame portion 30 has a rearend portion 31, an upper flat plate portion 32, a lower flat plateportion 33, fitting portions 33B, 33C, 33D, 33E, pillar portions 34A,34B, 34C, 34D, 34E, a support rib 35, a front end fitting portion 36, arear end fitting portion 37, a front upper fitting portion 38, and afront lower fitting portion 39. Each of them is formed to extend in thewidth direction (the direction of arrow AR shown in FIG. 11) of vehicleseat 1 (FIG. 1).

Rear frame portion 30 is also fabricated by being cut from an extrusionmaterial made of an aluminum alloy or a magnesium alloy having aconstant cross-sectional shape in the direction orthogonal to the widthdirection. Rear end portion 31, upper flat plate portion 32, front upperfitting portion 38, support rib 35, front lower fitting portion 39,front end fitting portion 36, lower flat plate portion 33 and rear endfitting portion 37 assume a continuous and closed annular shape (frameshape) as a whole.

Fitting Portions 33B, 33C, 33D, 33E, Front End Fitting Portion 36 andRear End Fitting Portion 37

Rear end portion 31 has the shape of a curved plate curved in asemi-circular arc. Upper flat plate portion 32 is continuous with anupper portion of rear end portion 31, and extends from the upper portionof rear end portion 31 toward the position of front upper fittingportion 38. The front side of a lower portion of rear end portion 31 isprovided with rear end fitting portion 37. Lower flat plate portion 33is provided between rear end fitting portion 37 and front end fittingportion 36. Fitting portions 33B, 33C, 33D and 33E are provided on alower surface of lower flat plate portion 33 to hang down therefrom. Thefront side of front end fitting portion 36 is provided with front lowerfitting portion 39.

Pillar portion 34A has the shape of a flat plate, and is provided so asto connect upper flat plate portion 32 and front lower fitting portion39. Pillar portion 34A extends obliquely upward and rearward from frontlower fitting portion 39 in the above-described state of the seatingposition (the state shown in FIG. 1). Pillar portions 34B, 34C, 34D and34E each have the shape of a flat plate, and are provided substantiallyparallel to one another so as to connect upper flat plate portion 32 andlower flat plate portion 33. Pillar portions 34B, 34C, 34D and 34Eextend in a direction generally orthogonal to lower flat plate portion33. Pillar portions 34B, 34C, 34D and 34E extend vertically upward fromlower flat plate portion 33 in the above-described state of the seatingposition.

Fitting portions 33B, 33C, 33D and 33E are provided between front endfitting portion 36 and rear end fitting portion 37. Fitting portions33B, 33C, 33D and 33E are located generally across lower flat plateportion 33 from pillar portions 34B, 34C, 34D and 34E, respectively. Inthe above-described state of the seating position, front end fittingportion 36 and fitting portions 33C, 33E each include a rearwardlyopening inner circumferential surface, and fitting portions 33B, 33D andrear end fitting portion 37 each include a forwardly opening innercircumferential surface.

Front Upper Fitting Portion 38 and Front Lower Fitting Portion 39

As shown in FIGS. 9 and 10, front upper fitting portion 38 is formed onthe front side of upper flat plate portion 32 (rear frame portion 30),and front lower fitting portion 39 is formed on the front side of frontend fitting portion 36 (rear frame portion 30). Rear upper fittingportion 28 and front upper fitting portion 38 are fitted together whilemaking slide-contact with each other in the width direction, while rearlower fitting portion 29 and front lower fitting portion 39 are fittedtogether while making slide-contact with each other in the widthdirection, thereby causing front frame portion 20 and rear frame portion30 to be integrated together to form side frame 10L. This is also thecase with side frame 10R (see FIGS. 3 to 6 and the like).

Front upper fitting portion 38 has an upwardly opening recessed shape inthe above-described state of the seating position (the state shown inFIG. 1). Front upper fitting portion 38 is provided with a front upperinclined surface 38T extending obliquely upward and rearward in theabove-described state of the seating position. Front upper inclinedsurface 38T is formed by a rearwardly facing portion of a surface offront upper fitting portion 38.

Front lower fitting portion 39 has a downwardly opening recessed shapein the above-described state of the seating position (the state shown inFIG. 1). Front lower fitting portion 39 is provided with a front lowerinclined surface 39T extending obliquely downward and forward in theabove-described state of the seating position. Front lower inclinedsurface 39T is formed by a rearwardly facing portion of a surface offront lower fitting portion 39.

When rear upper fitting portion 28 and front upper fitting portion 38are being fitted together, rear upper inclined surface 28T and frontupper inclined surface 38T are locked to each other (both elements arebrought into intimate contact with each other and thereby integrated tohave such a relation that they behave together). Similarly, when rearlower fitting portion 29 and front lower fitting portion 39 are beingfitted together, rear lower inclined surface 29T and front lowerinclined surface 39T are locked to each other.

Support Rib 35

Support rib 35 connecting front upper fitting portion 38 and front lowerfitting portion 39 is provided at a position of rear frame portion 30between front upper fitting portion 38 and front lower fitting portion39. Support rib 35 has the shape of a flat plate, and is providedsubstantially parallel to pillar portions 34B, 34C, 34D and 34E (FIG.2). Support rib 35 extends along a direction identical to the directiongenerally orthogonal to lower flat plate portion 33. Support rib 35extends along a direction generally parallel to the vertical directionin the above-described state of the seating position.

Cushion Panel 40

As shown in FIGS. 1 to 6, cushion panel 40 includes front panel portion50 and rear panel portion 60 configured as separate members. Whencushion panel 40 has been fixed to side frames 10L and 10R, front panelportion 50 and rear panel portion 60 are spaced apart from each other inthe front to rear direction.

Front Panel Portion 50

Referring mainly to FIGS. 2 and 7, front panel portion 50 provided oncushion panel 40 has a front end portion 51, an upper surface portion52, a lower surface portion 53, pillar portions 54A, 54B, a recessforming portion 55, and elastically deformed portions 56, 57. Each ofthem is formed to extend in the width direction (the direction of arrowAR shown in FIG. 7) of vehicle seat 1 (FIG. 1). Front panel portion 50is fabricated by being cut from an extrusion material made of analuminum alloy or a magnesium alloy having a constant cross-sectionalshape in the direction orthogonal to the width direction.

Front end portion 51 has the shape of a curved plate curved in asemi-circular arc, and a portion of front end portion 51 close to theend in the width direction is arranged on the inner side of front endportion 21. Upper surface portion 52 is continuous with an upper portionof front end portion 51, and extends in the form of a flat plate fromthe upper portion of front end portion 51 toward the position ofelastically deformed portion 57. Lower surface portion 53 is continuouswith a lower portion of front end portion 51, and extends in the form ofa flat plate from the lower portion of front end portion 51 toward theposition of elastically deformed portion 56. Upper surface portion 52and lower surface portion 53 are substantially parallel to each other.

Pillar portion 54A is provided to extend upward from a portion of lowersurface portion 53 located between front end portion 51 and elasticallydeformed portion 56 toward a portion (recess forming portion 55) ofupper surface portion 52 located between front end portion 51 andelastically deformed portion 57. Pillar portion 54A extends in the formof a flat plate, and is generally orthogonal to lower surface portion53. The tip end (upper end) of pillar portion 54A in its extendingdirection is provided with recess forming portion 55 which will bedescribed later.

Pillar portion 54B connects a portion of lower surface portion 53located between pillar portion 54A and elastically deformed portion 56,and a portion of upper surface portion 52 located between recess formingportion 55 and elastically deformed portion 57. Pillar portion 54B alsoextends in the form of a flat plate, and is generally orthogonal tolower surface portion 53.

Recess Forming Portion 55

Referring to FIGS. 7 and 8, front panel portion 50 in the presentembodiment includes a plurality of recess forming portions 55.Specifically, upper surface portion 52 is provided with a first recessforming portion 55F and a second recess forming portion 55B. Firstrecess forming portion 55F and second recess forming portion 55B arealso formed to extend in the width direction (the direction of arrow ARshown in FIG. 7).

First recess forming portion 55F includes a rearwardly opening innersurface 55FT, and second recess forming portion 55B includes a forwardlyopening inner surface 55BT. First recess forming portion 55F and secondrecess forming portion 55B are formed such that inner surfaces 55FT and55BT face each other in the front to rear direction in theabove-described state of the seating position (the state shown in FIG.1). An upwardly projecting protrusion 55U is formed between innersurfaces 55FT and 55BT.

Screw 70LA

As shown in FIGS. 3, 7 and 8, screw 70LA as an insertion member is usedto fix cushion panel 40 (front panel portion 50) to side frame 10L(front frame portion 20). Screw 70LA includes a shank 71 and a head 72.

Specifically, front frame portion 20 and front panel portion 50 areassembled together while making slide-contact with each other in thewidth direction, such that first piece portion 25FT of elasticallydeformed portion 25 is located on the inner side of first recess formingportion 55F and second piece portion 25BT of elastically deformedportion 25 is located on the inner side of second recess forming portion55B. In the assembled state, inner surface 55FT of first recess formingportion 55F faces an outer circumferential surface of first pieceportion 25FT (front end 25F), and inner surface 55BT of second recessforming portion 55B faces an outer circumferential surface of secondpiece portion 25BT (rear end 25B). A substantially cylindrical space isformed between the surface of protrusion 55U and inner circumferentialsurface 25S of elastically deformed portion 25. Shank 71 has a diameterlarger than this space, and is press fitted into this space from theouter side in the width direction.

The insertion of shank 71 on the inner side of inner circumferentialsurface 25S causes an increase in distance between first piece portion25FT (front end 25F) and second piece portion 25BT (rear end 25B). Theouter circumferential surface of first piece portion 25FT is expandedoutward (forward) (arrow DRSF), and the outer circumferential surface offirst piece portion 25FT expanded by the insertion of shank 71 isbrought into pressure contact with inner surface 55FT of first recessforming portion 55F. Similarly, the outer circumferential surface ofsecond piece portion 25BT is expanded outward (rearward) (arrow DR5B),and the outer circumferential surface of second piece portion 25BTexpanded by the insertion of shank 71 is brought into pressure contactwith inner surface 55BT of second recess forming portion 55B.

The insertion of shank 71 on the inner side of inner circumferentialsurface 25S also causes protrusion 55U to be biased away from suspendedportion 24A. With this biasing, inner surface 55FT of first recessforming portion 55F and inner surface 55BT of second recess formingportion 55B are also indirectly biased in the same direction, so thatinner surface 55FT and inner surface 55BT can be brought into morestrongly pressure contact with first piece portion 25FT and second pieceportion 25BT, respectively.

In this state, head 72 of screw 70LA is provided on the outer side ofshank 71 in the width direction, and can make contact with bothelastically deformed portion 25 and recess forming portion 55 (firstrecess forming portion 55F and second recess forming portion 55B) fromthe outer side in the width direction (FIG. 3), thereby definingrelative positions of elastically deformed portion 25 and recess formingportion 55 in the width direction. That is, an end face of head 72 onthe shank 71 side can be pressed against both an outer end face ofelastically deformed portion 25 and an outer end face of recess formingportion 55, to allow these outer end faces to be aligned flush with eachother.

Elastically Deformed Portion 56

Referring to FIGS. 7 and 8, elastically deformed portion 56 is providedat the rear end of lower surface portion 53 of front panel portion 50.Elastically deformed portion 56 includes curved portions 56A and 56Bextending in the width direction (the direction of arrow AR). Curvedportions 56A and 56B face each other, and extend such that eachdescribes a semi-circular arc rearward from the rear end of lowersurface portion 53. An inner circumferential surface 56S of elasticallydeformed portion 56 has a surface shape which is substantially C-shaped.

Screw 70LB

As shown in FIGS. 3, 7 and 8, screw 70LB as an insertion member alsoincludes shank 71 and head 72. Front frame portion 20 and front panelportion 50 are assembled together while making slide-contact with eachother in the width direction, such that elastically deformed portion 56is located on the inner side of recess forming portion 26. In theassembled state, inner surface 26S of recess forming portion 26 faces anouter circumferential surface of elastically deformed portion 56. Asubstantially cylindrical space is formed between the surface ofprotrusion 26U and inner circumferential surface 56S of elasticallydeformed portion 56. Shank 71 has a diameter larger than this space, andis press fitted into this space from the outer side in the widthdirection.

The insertion of shank 71 on the inner side of inner circumferentialsurface 56S causes the outer circumferential surface of elasticallydeformed portion 56 (curved portions 56A and 56B) to be expanded outward(arrows DR6U and DR6D), and the outer circumferential surface ofelastically deformed portion 56 expanded by the insertion of shank 71 isbrought into pressure contact with inner surface 26S of recess formingportion 26.

The insertion of shank 71 on the inner side of inner circumferentialsurface 56S also causes protrusion 26U to be biased such that it isdisplaced rearward. With this biasing, inner surface 26S of recessforming portion 26 is also indirectly biased in the same direction, sothat inner surface 26S can be brought into more strongly pressurecontact with the outer circumferential surface of elastically deformedportion 56.

In this state, head 72 of screw 70LB is provided on the outer side ofshank 71 in the width direction, and can make contact with bothelastically deformed portion 56 and recess forming portion 26 from theouter side in the width direction (FIG. 3), thereby defining relativepositions of elastically deformed portion 56 and recess forming portion26 in the width direction. That is, an end face of head 72 on the shank71 side can be pressed against both an outer end face of elasticallydeformed portion 56 and an outer end face of recess forming portion 26,thereby allowing these outer end faces to be aligned flush with eachother.

Elastically Deformed Portion 57

Referring to FIGS. 7 and 8, elastically deformed portion 57 is providedat the rear end of upper surface portion 52 of front panel portion 50.Elastically deformed portion 57 includes curved portions 57A and 57Bextending in the width direction (the direction of arrow AR). Curvedportions 57A and 57B face each other, and extend such that eachdescribes a semi-circular arc rearward from the rear end of uppersurface portion 52. An inner circumferential surface 57S of elasticallydeformed portion 57 has a surface shape which is substantially C-shaped.

Screw 70LC

As shown in FIGS. 3, 7 and 8, screw 70LC as an insertion member alsoincludes shank 71 and head 72. Front frame portion 20 and front panelportion 50 are assembled together while making slide-contact with eachother in the width direction, such that elastically deformed portion 57is located on the inner side of recess forming portion 27. In theassembled state, inner surfaces 27AS and 27BS of recess forming portion27 face an outer circumferential surface of elastically deformed portion57. A substantially cylindrical space is formed between the surface ofprotrusion 27U and inner circumferential surface 57S of elasticallydeformed portion 57. Shank 71 has a diameter larger than this space, andis press fitted into this space from the outer side in the widthdirection.

The insertion of shank 71 on the inner side of inner circumferentialsurface 57S causes the outer circumferential surface of elasticallydeformed portion 57 (curved portions 57A and 57B) to be expanded outward(arrows DR7U and DR7D), and the outer circumferential surface ofelastically deformed portion 57 expanded by the insertion of shank 71 isbrought into pressure contact with inner surfaces 27AS and 27BS ofrecess forming portion 27.

The insertion of shank 71 on the inner side of inner circumferentialsurface 57S also causes protrusion 27U to be biased such that it isdisplaced rearward. With this biasing, inner surfaces 27AS and 27BS ofrecess forming portion 27 are also indirectly biased in the samedirection, so that inner surfaces 27AS and 27BS can be brought into morestrongly pressure contact with the outer circumferential surface ofelastically deformed portion 57.

In this state, head 72 of screw 70LC is provided on the outer side ofshank 71 in the width direction, and can make contact with bothelastically deformed portion 57 and recess forming portion 27 from theouter side in the width direction (FIG. 3), thereby defining relativepositions of elastically deformed portion 57 and recess forming portion27 in the width direction. That is, an end face of head 72 on the shank71 side can be pressed against both an outer end face of elasticallydeformed portion 57 and an outer end face of recess forming portion 27,thereby allowing these outer end faces to be aligned flush with eachother.

As shown in FIG. 3, the assembly configuration using screws 70LA, 70LBand 70LC as described above is applied between front frame portion 20 ofside frame 10L and front panel portion 50. By using screws 70RA, 70RBand 70RC, an assembly configuration similar to the above is also appliedbetween front frame portion 20 of side frame 10R and front panel portion50. Head 72 of each screw can be utilized to allow the outer end face offront frame portion 20 of side frame 10L and the outer end face of frontpanel portion 50 in the width direction to be readily aligned flush witheach other, and also allow the outer end face of front frame portion 20of side frame 10R and the outer end face of front panel portion 50 inthe width direction to be readily aligned flush with each other.

Rear Panel Portion 60

Referring mainly to FIGS. 11 and 12, rear panel portion 60 provided oncushion panel 40 has a base portion 63, reinforcing ribs 63B, 63C, 63D,63E, corrugated portions 64, a front end rib 66, and a rear end rib 67.Each of them is formed to extend in the width direction (the directionof arrow AR shown in FIG. 11) of vehicle seat 1 (FIG. 1). Rear panelportion 60 is also fabricated by being cut from an extrusion materialmade of an aluminum alloy or a magnesium alloy having a constantcross-sectional shape in the direction orthogonal to the widthdirection.

Base Portion 63, Front End Rib 66 and Rear End Rib 67

Base portion 63 is formed as a plate, and has a substantiallyrectangular outer shape in plan view (FIG. 3). In the above-describedstate of the seating position (the state shown in FIG. 1), front end rib66 is provided at the front end of base portion 63, and rear end rib 67is provided at the rear end of base portion 63 (on a rear side relativeto front end rib 66). Each of front end rib 66 and rear end rib 67extends in the width direction.

As shown in FIG. 12, front end rib 66 includes an upwardly extendingportion 66A provided at the front end of base portion 63, and a hookportion 66B provided at the upper end of upwardly extending portion 66Aand formed to face forward. Rear end rib 67 includes an upwardlyextending portion 67A provided at the rear end of base portion 63, and ahook portion 67B provided at the upper end of upwardly extending portion67A and formed to face rearward.

Reinforcing Ribs 63B, 63C, 63D and 63E

Reinforcing ribs 63B, 63C, 63D and 63E are provided on base portion 63between front end rib 66 and rear end rib 67, and formed such that theyare arranged at a distance from one another in the front to reardirection. Each of reinforcing ribs 63B and 63D includes an upwardlyextending portion 61, and a hook portion 62 provided at the upper end ofupwardly extending portion 61 and formed to face rearward. Each ofreinforcing ribs 63C and 63E includes upwardly extending portion 61, andhook portion 62 provided at the upper end of upwardly extending portion61 and formed to face forward. Reinforcing ribs 63B, 63C, 63D and 63Eare provided such that the reinforcing ribs each formed with forwardlyfacing hook portion 62 (reinforcing ribs 63C and 63E) and thereinforcing ribs each formed with rearwardly facing hook portion 62(reinforcing ribs 63B and 63E) are alternately arranged.

Corrugated Portions 64

A portion of base portion 63 between adjacent reinforcing ribs 63B and63C is provided with corrugated portion 64 formed to have a curvedcross-sectional shape in the direction orthogonal to the widthdirection. This is also the case with a portion of base portion 63between adjacent reinforcing ribs 63C and 63D, and a portion of baseportion 63 between adjacent reinforcing ribs 63D and 63E. This is alsothe case with a portion of base portion 63 between front end rib 66 andreinforcing rib 63B, and a portion of base portion 63 between rear endrib 67 and reinforcing rib 63E. In the present embodiment, when rearpanel portion 60 has been assembled to rear frame portion 30, each ofthe plurality of corrugated portions 64 has a curved cross-sectionalshape protruding toward lower flat plate portion 33. The curve may be ina direction opposite to this direction, and corrugated portion 64 is notlimited to have a curved cross-sectional shape but may have a bentcross-sectional shape.

Rear panel portion 60 and rear frame portion 30 are assembled togetherwhile making slide-contact with each other in the width direction, suchthat front end rib 66, reinforcing ribs 63B, 63C, 63D, 63E and rear endrib 67 of rear panel portion 60 are located on the inner side of frontend fitting portion 36, fitting portions 33B, 33C, 33D, 33E and rear endfitting portion 37 of rear frame portion 30, respectively. Each of theseribs is fitted to each of these fitting portions, to thereby connectcushion panel 40 (rear panel portion 60) and side frame 10L (rear frameportion 30). The connection configuration as described above issimilarly applied as a connection configuration between rear frameportion 30 of side frame 10R and rear panel portion 60 (see FIGS. 3 to5).

SUMMARY

As described above, front frame portion 20 of each of side frames 10Land 10R and front panel portion 50 provided on cushion panel 40 arefixed together in the mode as shown in FIGS. 7 and 8. Front frameportion 20 and rear frame portion 30 of each of side frames 10L and 10Rare fixed together in the mode as shown in FIGS. 9 and 10. Rear frameportion 30 of each of side frames 10L and 10R and rear panel portion 60provided on cushion panel 40 are fixed together in the mode as shown inFIGS. 11 and 12. Side frames 10L, 10R and cushion panel 40 in thepresent embodiment shown in FIGS. 4 to 6 and the like are integratedtogether by adopting these fixing structures.

In the present embodiment, front frame portion 20 and front panelportion 50 are fixed together using a fastening structure includingscrews 70LA, 70LB, 70LC, 70RA, 70RB, 70RC (FIG. 3) as insertion members,elastically deformed portions 25, 56, 57, and recess forming portions55, 26, 27. These front frame portion 20 and front panel portion 50constituting the framework of vehicle seat 1 (FIG. 1) can be joinedtogether without using a welding process. As such, manufacturing costswhich do not involve the costs for welding equipment and a weldingprocess can be reduced. According to the present embodiment,manufacturing costs can be reduced for a similar reason even incomparison to an example where they are joined using rivets and thelike.

In the fastening structure using screws 70LA, 70LB, 70LC, 70RA, 70RB and70RC (see FIG. 3), head 72 of each screw can be utilized to allow theouter end face of front frame portion 20 of side frame 10L and the outerend face of front panel portion 50 in the width direction to be readilyaligned flush with each other, and also allow the outer end face offront frame portion 20 of side frame 10R and the outer end face of frontpanel portion 50 in the width direction to be readily aligned flush witheach other.

In the present embodiment (FIGS. 7 and 8), upper surface portion 52 offront panel portion 50 is provided with first recess forming portion 55Fand second recess forming portion 55B. Upper surface portion 52 may beprovided with only one of these recess forming portions as needed. Innersurface 55FT of first recess forming portion 55F and inner surface 55BTof second recess forming portion 55B are formed to open in oppositedirections (that is, to face each other), and first piece portion 25FTand second piece portion 25BT of elastically deformed portion 25 extendin opposite directions to enter inner surface 55FT and inner surface55BT, respectively. With this configuration, both forward and rearwardmovements of front panel portion 50 relative to front frame portion 20can be effectively regulated.

In the present embodiment (FIGS. 7 and 8), front end portion 51 of frontpanel portion 50 is arranged on the inner side of front end portion 21of front frame portion 20 while in contact therewith, and furthermore,elastically deformed portions 56 and 57 are provided at the rear ends offront panel portion 50 and fixed to recess forming portions 26 and 27,respectively. Even if a load from back to front acts on front panelportion 50, the load can be received not only by a portion where frontend portions 21 and 51 are in contact with each other, but also by aportion where elastically deformed portion 56 and recess forming portion26 are fixed together, and further by a portion where elasticallydeformed portion 57 and recess forming portion 27 are fixed together.Even under the action of such a load, forward separation of front panelportion 50 from right and left front frame portions 20 can besufficiently suppressed.

In the present embodiment, rear panel portion 60 of cushion panel 40 isprovided with reinforcing ribs 63B, 63C, 63D and 63E extending in thewidth direction, and rear frame portion 30 of each of side frames 10Land 10R is provided with fitting portions 33B, 33C, 33D and 33Eextending in the width direction. These reinforcing ribs are fitted tothese fitting portions, respectively, to thereby connect rear panelportion 60 and right and left rear frame portions 30. Reinforcing ribs63B, 63C, 63D and 63E can perform not only the function of improving thestrength of rear panel portion 60, but also the function of connectingrear panel portion 60 and right and left rear frame portions 30. Owingto the presence of reinforcing ribs 63B, 63C, 63D and 63E that alsofunction as connection means, it is not particularly necessary toimprove the strength of rear panel portion 60 by providing beads with apressing machine or the like after the rear panel portion has beenformed, whereby lowered processing costs and high productivity can beexpected.

In the present embodiment, rear panel portion 60 is provided with frontend rib 66 and rear end rib 67, and the pair of side frames 10L and 10R(rear panel portion 60) is provided with front end fitting portion 36that is fitted to front end rib 66, and rear end fitting portion 37 thatis fitted to rear end rib 67. Rear panel portion 60 can be connected atits front end and rear end to rear frame portion 30 by a stablestructure with greater holding power. Front end rib 66 and rear end rib67 perform not only the function of connecting rear panel portion 60 andright and left rear frame portions 30, but also the function ofimproving the strength of rear panel portion 60 because the ribs extendin the width direction from rear frame portion 30 of side frame 10L toreach rear frame portion 30 of side frame 10R.

In the present embodiment, corrugated portion 64 formed to have a curvedor bent cross-sectional shape in the direction orthogonal to the widthdirection is provided at a portion between two adjacent ones of frontend rib 66, rear end rib 67 and reinforcing ribs 63B, 63C, 63D, 63E.With corrugated portions 64, front end rib 66 and reinforcing ribs 63C,63E are more likely to tilt rearward and reinforcing ribs 63B, 63D andrear end rib 67 are more likely to tilt forward than when the portionswhere corrugated portions 64 are provided are formed as a flat(straight) plate. Accordingly, when assembling rear panel portion 60 andrear frame portion 30 together, they can be assembled together whilereadily making slide-contact with each other in the width direction.

In the present embodiment, reinforcing ribs 63B, 63C, 63D and 63E areprovided such that the reinforcing ribs each formed with forwardlyfacing hook portion 62 (reinforcing ribs 63C and 63E) and thereinforcing ribs each formed with rearwardly facing hook portion 62(reinforcing ribs 63B and 63E) are alternately arranged. When rear panelportion 60 and rear frame portion 30 have been assembled together, aconnected structure well balanced in the front to rear direction can beimplemented, so that the action of stress on a partial connected portionin a concentrated manner can be suppressed.

In the present embodiment, the rear portion of front frame portion 20 isprovided with rear upper fitting portion 28 and rear lower fittingportion 29 extending in the width direction, and the front portion ofrear frame portion 30 is provided with front upper fitting portion 38and front lower fitting portion 39 extending in the width direction.Front frame portion 20 and rear frame portion 30 can be fitted togetherwhile making slide-contact with each other (by a so-called sliding fit)to thereby readily form side frame 10L having them integrated together,while another front frame portion 20 and another rear frame portion 30can also be fitted together while making slide-contact with each otherto thereby readily form side frame 10R having them integrated together.

FIG. 13 is a side view illustrating a function and effect of vehicleseat 1 in the embodiment. As described above, under normal conditions,seat cushion 3 (FIG. 1) is fixed in the state of the seating positionwhere it is collapsed on base 4 (cushion rubber 4A), and held in thestate that allows the seated passenger to sit on the upper side of seatcushion 3. Assume that a load as indicated by an arrow AR0 in FIG. 13acts on upper surface portion 52 of front panel portion 50 in thisstate. This load also acts on a portion of front frame portion 20coupled to front panel portion 50 that is close to front end portion 21as indicated by an arrow AR1, and also acts on a portion of front frameportion 20 that is close to rear upper fitting portion 28 as indicatedby an arrow AR2. The entire upper flat plate portion 22 is biased suchthat it is displaced in a direction identical to the direction indicatedby arrow AR0 (that is, obliquely downward and forward).

In the present embodiment, rear upper fitting portion 28 has aprotruding shape extending downward from above, and front upper fittingportion 38 has an upwardly opening recessed shape. Even if front upperfitting portion 38 receives the load as indicated by arrow AR2 from rearupper fitting portion 28, front upper fitting portion 38 can oppose theload by virtue of having the upwardly opening recessed shape, therebysuppressing the release of the fitting between rear upper fittingportion 28 and front upper fitting portion 38.

Furthermore, in the present embodiment, rear upper fitting portion 28 isprovided with rear upper inclined surface 28T extending obliquelydownward and forward, and front upper fitting portion 38 is providedwith front upper inclined surface 38T extending obliquely upward andrearward, with rear upper inclined surface 28T and front upper inclinedsurface 38T being locked to each other. This locked structure can opposethe displacement of rear upper fitting portion 28 in the directionindicated by arrow AR2 (that is, obliquely downward and forward) and theforward displacement of rear upper fitting portion 28, thereby furthersuppressing the release of the fitting between rear upper fittingportion 28 and front upper fitting portion 38.

A portion of front frame portion 20 on the cushion rubber 4A side (rearend side) has relatively high structural rigidity and thereforefunctions as a fixed end, while a portion of front frame portion 20 onthe front end portion 21 side has lower structural rigidity than thefixed end and therefore acts as a free end, so that front frame portion20 is generally supported in a cantilever manner as a whole.Accordingly, when a load as indicated by arrow AR1 acts on a portion offront frame portion 20 close to front end portion 21, the load acts asan upward load as indicated by an arrow AR3 at a position in thevicinity of rear lower fitting portion 29.

In the present embodiment, rear lower fitting portion 29 has aprotruding shape extending upward from below, and front lower fittingportion 39 has a downwardly opening recessed shape. Even if front lowerfitting portion 39 receives the load as indicated by arrow AR3 from rearlower fitting portion 29, front lower fitting portion 39 can oppose theload by virtue of having the downwardly opening recessed shape, therebysuppressing the release of the fitting between rear lower fittingportion 29 and front lower fitting portion 39.

Furthermore, in the present embodiment, rear lower fitting portion 29 isprovided with rear lower inclined surface 29T extending obliquely upwardand rearward, and front lower fitting portion 39 is provided with frontlower inclined surface 39T extending obliquely downward and forward,with rear lower inclined surface 29T and front lower inclined surface39T being locked to each other. This locked structure can oppose thedisplacement of rear lower fitting portion 29 in the direction indicatedby arrow AR3 (that is, obliquely upward and rearward) and the forwarddisplacement of rear lower fitting portion 29, thereby furthersuppressing the release of the fitting between rear lower fittingportion 29 and front lower fitting portion 39.

In the present embodiment, support rib 35 connecting front upper fittingportion 38 and front lower fitting portion 39 is provided at a portionof rear frame portion 30 between front upper fitting portion 38 andfront lower fitting portion 39. The relative movement between frontupper fitting portion 38 and front lower fitting portion 39 is regulatedby the presence of support rib 35. Support rib 35 opposes (arrow AR4)biasing of rear upper fitting portion 28 and front upper fitting portion38 such that they are displaced in the direction indicated by arrow AR2(that is, downward), and also opposes (arrow AR5) biasing of rear lowerfitting portion 29 and front lower fitting portion 39 such that they aredisplaced in the direction indicated by arrow AR3 (that is, upward).Accordingly, the release of the fitting between rear upper fittingportion 28 and front upper fitting portion 38 can be effectivelysuppressed, and the release of the fitting between rear lower fittingportion 29 and front lower fitting portion 39 can also be effectivelysuppressed.

In the present embodiment, front panel portion 50 forming part ofcushion panel 40 and rear panel portion 60 forming part of cushion panel40 are formed by being cut from an extrusion material made of analuminum alloy or a magnesium alloy having a constant cross-sectionalshape in the direction orthogonal to the width direction. It is possiblenot only to readily fabricate front panel portion 50 and rear panelportion 60 having these configurations, but also to readily implementthe application of each configuration described above to them. Frontpanel portion 50 and rear panel portion 60 may be integrally configured,and the entire cushion panel 40 may be fabricated as a single member bybeing cut from an extrusion material made of an aluminum alloy or amagnesium alloy having a constant cross-sectional shape in the directionorthogonal to the width direction.

In the present embodiment, front frame portion 20 forming part of sideframe 10L and rear frame portion 30 forming part of side frame 10L areformed by being cut from an extrusion material made of an aluminum alloyor a magnesium alloy having a constant cross-sectional shape in thedirection orthogonal to the width direction. This is also the case withside frame 10R, and side frame 10L and side frame 10R can utilize frontframe portions 20 having the same configuration and rear frame portions30 having the same configuration. It is possible not only to readilyfabricate front frame portion 20 and rear frame portion 30 having theseconfigurations, but also to readily implement the application of eachconfiguration described above to them. Front frame portion 20 and rearframe portion 30 may be integrally configured, and the entire side frame10L may be fabricated as a single member by being cut from an extrusionmaterial made of an aluminum alloy or a magnesium alloy having aconstant cross-sectional shape in the direction orthogonal to the widthdirection. This is also the case with side frame 10R.

Variation of Embodiment

FIG. 14 is a side view regarding a vehicle seat in a variation of theembodiment, which shows front frame portion 20 and rear frame portion 30provided on side frame 10L in an assembled state in this variation.Vehicle seat 1 in the embodiment (FIG. 1) and the vehicle seat in thepresent variation are different on the following point.

The vehicle seat in the present variation has screws 78L and 79L asinsertion members for fixing front frame portion 20 and rear frameportion 30 together. Screw 78L as an insertion member includes shank 71and head 72, and screw 79L as an insertion member also includes shank 71and head 72.

Rear Upper Fitting Portion 28J, Front Upper Fitting Portion 38J, andScrew 78L

The rear end of upper flat plate portion 22 of front frame portion 20 isprovided with a rear upper fitting portion 28J (which also functions asan elastically deformed portion). Rear upper fitting portion 28Jincludes curved portions 28A and 28B extending in the width direction.Curved portions 28A and 28B face each other, and extend such that eachdescribes a semi-circular arc rearward from the rear end of upper flatplate portion 22. An inner circumferential surface 28S of rear upperfitting portion 28J has a surface shape which is substantially C-shaped.

The front end of upper flat plate portion 32 of rear frame portion 30 isprovided with a front upper fitting portion 38J (which also functions asa recess forming portion). Front upper fitting portion 38J includescurved portions 38A and 38B extending in the width direction. Curvedportions 38A and 38B face each other, and extend such that eachdescribes a semi-circular arc forward from the front end of upper flatplate portion 32. Curved portions 38A and 38B of front upper fittingportion 38J include inner surfaces 38AS and 38BS, respectively.

Front frame portion 20 and rear frame portion 30 are assembled togetherwhile making slide-contact with each other in the width direction, suchthat rear upper fitting portion 28J is located on the inner side offront upper fitting portion 38J. In the assembled state, inner surfaces38AS and 38BS of front upper fitting portion 38J face an outercircumferential surface of rear upper fitting portion 28J (curvedportions 28A and 28B). A substantially cylindrical space is formed onthe inner side of inner circumferential surface 28S of rear upperfitting portion 28J. Shank 71 has a diameter larger than this space, andis press fitted into this space from the outer side in the widthdirection.

The insertion of shank 71 on the inner side of inner circumferentialsurface 28S causes the outer circumferential surface of rear upperfitting portion 28J (curved portions 28A and 28B) to be expandedoutward, and the outer circumferential surface of rear upper fittingportion 28J expanded by the insertion of shank 71 is brought intopressure contact with inner surfaces 38AS and 38BS of front upperfitting portion 38J. In this state, head 72 of screw 78L is provided onthe outer side of shank 71 in the width direction, and can make contactwith both rear upper fitting portion 28J and front upper fitting portion38J from the outer side in the width direction, thereby definingrelative positions of rear upper fitting portion 28J and front upperfitting portion 38J in the width direction. That is, an end face of head72 on the shank 71 side can be pressed against both an outer end face ofrear upper fitting portion 28J and an outer end face of front upperfitting portion 38J, thereby allowing these outer end faces to bealigned flush with each other.

Rear Lower Fitting Portion 29J, Front Lower Fitting Portion 39J, andScrew 79L

The rear end of lower flat plate portion 23B of front frame portion 20is provided with a rear lower fitting portion 29J (which also functionsas an elastically deformed portion). Rear lower fitting portion 29Jincludes curved portions 29A and 29B extending in the width direction.Curved portions 29A and 29B face each other, and extend such that eachdescribes a semi-circular arc obliquely upward and rearward from therear end of lower flat plate portion 23B. An inner circumferentialsurface 29S of rear lower fitting portion 29J has a surface shape whichis substantially C-shaped.

The front side of front end fitting portion 36 of rear frame portion 30is provided with a front lower fitting portion 39J (which also functionsas a recess forming portion). Front lower fitting portion 39J includescurved portions 39A and 39B extending in the width direction. Curvedportions 39A and 39B face each other, and extend such that eachdescribes a semi-circular arc obliquely downward and forward from thefront side of front end fitting portion 36. Curved portions 39A and 39Bof front lower fitting portion 39J include inner surfaces 39AS and 39BS,respectively.

Front frame portion 20 and rear frame portion 30 are assembled togetherwhile making slide-contact with each other in the width direction, suchthat rear lower fitting portion 29J is located on the inner side offront lower fitting portion 39J. In the assembled state, inner surfaces39AS and 39BS of front lower fitting portion 39J face an outercircumferential surface of rear lower fitting portion 29J (curvedportions 29A and 29B). A substantially cylindrical space is formed onthe inner side of inner circumferential surface 29S of rear lowerfitting portion 29J. Shank 71 has a diameter larger than this space, andis press fitted into this space from the outer side in the widthdirection.

The insertion of shank 71 on the inner side of inner circumferentialsurface 29S causes the outer circumferential surface of rear lowerfitting portion 29J (curved portions 29A and 29B) to be expandedoutward, and the outer circumferential surface of rear lower fittingportion 29J expanded by the insertion of shank 71 is brought intopressure contact with inner surfaces 39AS and 39BS of front lowerfitting portion 39J. In this state, head 72 of screw 79L is provided onthe outer side of shank 71 in the width direction, and can make contactwith both rear lower fitting portion 29J and front lower fitting portion39J from the outer side in the width direction, thereby definingrelative positions of rear lower fitting portion 29J and front lowerfitting portion 39J in the width direction. That is, an end face of head72 on the shank 71 side can be pressed against both an outer end face ofrear lower fitting portion 29J and an outer end face of front lowerfitting portion 39J, thereby allowing these outer end faces to bealigned flush with each other.

In the present variation, front frame portion 20 and rear frame portion30 are fixed together using a fastening structure including screws 78Land 79L (FIG. 3) as insertion members, rear upper fitting portion 28Jand rear lower fitting portion 29J as elastically deformed portions, andfront upper fitting portion 38J and front lower fitting portion 39J asrecess forming portions. These front frame portion 20 and rear frameportion 30 constituting the framework of the vehicle seat can be joinedtogether without using a welding process. As such, manufacturing costswhich do not involve the costs for welding equipment and a weldingprocess can be reduced. According to the present variation,manufacturing costs can be reduced for a similar reason even incomparison to an example where they are joined using rivets and thelike.

The above contents of the present disclosure could be summarized asfollows.

A vehicle seat based on one aspect of the present disclosure includes:first and second side frames arranged at a distance from each other in awidth direction; a cushion panel arranged between the first and secondside frames; and an insertion member for fixing the cushion panel to thefirst side frame, one of the side frame and the cushion panel beingprovided with an elastically deformed portion, the elastically deformedportion being formed to extend in the width direction and including anouter circumferential surface and an inner circumferential surface, theouter circumferential surface being configured to be expanded outward byinsertion of the insertion member on the inner side of the innercircumferential surface, the other of the first side frame and thecushion panel not provided with the elastically deformed portion beingprovided with a recess forming portion, the recess forming portion beingformed to extend in the width direction and facing the outercircumferential surface of the elastically deformed portion, the recessforming portion having an inner surface configured to be brought intopressure contact with the outer circumferential surface expanded byinsertion of the insertion member.

According to the vehicle seat described above, the first side frame andthe cushion panel are fixed together using a fastening structureincluding the insertion member, the elastically deformed portion, andthe recess forming portion. The first side frame and cushion panelconstituting the framework of the vehicle seat can be joined togetherwithout using a welding process. As such, manufacturing costs which donot involve the costs for welding equipment and a welding process can bereduced. According to the vehicle seat described above, manufacturingcosts can be reduced for a similar reason even in comparison to anexample where they are joined using rivets and the like.

In the vehicle seat described above, the insertion member may include ashank inserted on the inner side the inner circumferential surface, anda head provided on the outer side of the shank in the width direction,and making contact with both the elastically deformed portion and therecess forming portion from the outer side in the width direction so asto define relative positions of the elastically deformed portion and therecess forming portion in the width direction.

According to the vehicle seat described above, the head of the insertionmember can be utilized to allow an outer end face of the first sideframe and an outer end face of the cushion panel in the width directionto be readily aligned flush with each other.

In the vehicle seat described above, the cushion panel may include anupper surface portion provided with a first recess forming portion, theother of the first side frame and the cushion panel may be provided witha plurality of the recess forming portions including a first recessforming portion and a second recess forming portion, the first recessforming portion being provided at the upper surface portion andextending in the width direction, the second recess forming portionbeing provided at the upper surface portion and extending in the widthdirection, and the first recess forming portion and the second recessforming portion being formed to face each other in a front to reardirection, and the elastically deformed portion may include a firstpiece portion arranged on the inner side of the first recess formingportion, and a second piece portion arranged on the inner side of thesecond recess forming portion and configured to be displaced such that adistance between the first piece portion and the second piece portionincreases by the insertion of the insertion member.

According to the vehicle seat described above, both forward and rearwardmovements of the cushion panel relative to the first side frame can beeffectively regulated.

In the vehicle seat described above, the cushion panel may include afront panel portion and a rear panel portion configured as mutuallyseparate members, and the elastically deformed portion may be providedat a rear end of the front panel portion.

According to the vehicle seat described above, forward separation of thecushion panel from the first side frame can be suppressed.

A vehicle seat based on another aspect of the present disclosureincludes: a pair of side frames arranged at a distance from each otherin a width direction and each including a front frame portion and a rearframe portion; a cushion panel arranged between the pair of side frames;and an insertion member for fixing the front frame portion and the rearframe portion together, one of the front frame portion and the rearframe portion being provided with an elastically deformed portion, theelastically deformed portion being formed to extend in the widthdirection and including an outer circumferential surface and an innercircumferential surface, the outer circumferential surface beingconfigured to be expanded outward by insertion of the insertion memberon the inner side of the inner circumferential surface, the other of thefront frame portion and the rear frame portion being provided with arecess forming portion, the recess forming portion being formed toextend in the width direction and facing the outer circumferentialsurface of the elastically deformed portion, the recess forming portionhaving an inner surface configured to be brought into pressure contactwith the outer circumferential surface expanded by insertion of theinsertion member.

According to the vehicle seat described above, the front frame portionand the rear frame portion are fixed together using a fasteningstructure including the insertion member, the elastically deformedportion, and the recess forming portion. These front frame portion andrear frame portion constituting the framework of the vehicle seat can bejoined together without using a welding process. As such, manufacturingcosts which do not involve the costs for welding equipment and a weldingprocess can be reduced. According to the vehicle seat described above,manufacturing costs can be reduced for a similar reason even incomparison to an example where they are joined using rivets and thelike.

In the vehicle seat described above, a part or a whole of the cushionpanel may be formed by being cut from an extrusion material made of analuminum alloy or a magnesium alloy having a constant cross-sectionalshape in a direction orthogonal to the width direction.

According to the vehicle seat described above, it is possible not onlyto readily fabricate a part or a whole of the cushion panel, but also toreadily implement the application of each configuration described above.

In the vehicle seat described above, a part or a whole of the first sideframe may be formed by being cut from an extrusion material made of analuminum alloy or a magnesium alloy having a constant cross-sectionalshape in a direction orthogonal to the width direction.

According to the vehicle seat described above, it is possible not onlyto readily fabricate a part or a whole of the first side frame, but alsoto readily implement the application of each configuration describedabove.

In the vehicle seat described above, a part or a whole of the pair ofside frames may be formed by being cut from an extrusion material madeof an aluminum alloy or a magnesium alloy having a constantcross-sectional shape in a direction orthogonal to the width direction.

According to the vehicle seat described above, it is possible not onlyto readily fabricate a part or a whole of the pair of side frames, butalso to readily implement the application of each configurationdescribed above.

Although the embodiments of the present disclosure have been described,it should be understood that the embodiments disclosed herein areillustrative and non-restrictive in every respect. The scope of thepresent invention is defined by the terms of the claims, and is intendedto include any modifications within the meaning and scope equivalent tothe terms of the claims.

What is claimed is:
 1. A vehicle seat comprising: first and second sideframes arranged at a distance from each other in a width direction; acushion panel arranged between the first and second side frames; and aninsertion member for fixing the cushion panel to the first side frame,one of the first side frame and the cushion panel being provided with anelastically deformed portion, the elastically deformed portion beingformed to extend in the width direction and including an outercircumferential surface and an inner circumferential surface, the outercircumferential surface being configured to be expanded outward byinsertion of the insertion member on the inner side of the innercircumferential surface, the other of the first side frame and thecushion panel being provided with a recess forming portion, the recessforming portion being formed to extend in the width direction and facingthe outer circumferential surface of the elastically deformed portion,the recess forming portion having an inner surface configured to bebrought into pressure contact with the outer circumferential surfaceexpanded by the insertion of the insertion member.
 2. The vehicle seataccording to claim 1, wherein the insertion member includes a shankinserted on the inner side of the inner circumferential surface, and ahead provided on the outer side of the shank in the width direction, andmaking contact with both the elastically deformed portion and the recessforming portion from the outer side in the width direction so as todefine relative positions of the elastically deformed portion and therecess forming portion in the width direction.
 3. The vehicle seataccording to claim 1, wherein the cushion panel includes an uppersurface portion, the other of the first side frame and the cushion panelis provided with a plurality of the recess forming portions including afirst recess forming portion and a second recess forming portion, thefirst recess forming portion being provided at the upper surface portionand extending in the width direction, the second recess forming portionbeing provided at the upper surface portion and extending in the widthdirection, and the first recess forming portion and the second recessforming portion being formed to face each other in a front to reardirection, and the elastically deformed portion includes a first pieceportion arranged on the inner side of the first recess forming portion,and a second piece portion arranged on the inner side of the secondrecess forming portion and configured to be displaced such that adistance between the first piece portion and the second piece portionincreases by the insertion of the insertion member.
 4. The vehicle seataccording to claim 1, wherein the cushion panel includes a front panelportion and a rear panel portion configured as mutually separatemembers, and the elastically deformed portion is provided at a rear endof the front panel portion.
 5. A vehicle seat comprising: a pair of sideframes arranged at a distance from each other in a width direction andeach including a front frame portion and a rear frame portion; a cushionpanel arranged between the pair of side frames; and an insertion memberfor fixing the front frame portion and the rear frame portion together,one of the front frame portion and the rear frame portion being providedwith an elastically deformed portion, the elastically deformed portionbeing formed to extend in the width direction and including an outercircumferential surface and an inner circumferential surface, the outercircumferential surface being configured to be expanded outward byinsertion of the insertion member on the inner side of the innercircumferential surface, the other of the front frame portion and therear frame portion being provided with a recess forming portion, therecess forming portion being formed to extend in the width direction andfacing the outer circumferential surface of the elastically deformedportion, the recess forming portion having an inner surface configuredto be brought into pressure contact with the outer circumferentialsurface expanded by insertion of the insertion member.
 6. The vehicleseat according to claim 1, wherein a part or a whole of the cushionpanel is formed by being cut from an extrusion material made of analuminum alloy or a magnesium alloy having a constant cross-sectionalshape in a direction orthogonal to the width direction.
 7. The vehicleseat according to claim 5, wherein a part or a whole of the cushionpanel is formed by being cut from an extrusion material made of analuminum alloy or a magnesium alloy having a constant cross-sectionalshape in a direction orthogonal to the width direction.
 8. The vehicleseat according to claim 1, wherein a part or a whole of the first sideframes is formed by being cut from an extrusion material made of analuminum alloy or a magnesium alloy having a constant cross-sectionalshape in a direction orthogonal to the width direction.
 9. The vehicleseat according to claim 5, wherein a part or a whole of the pair of sideframes is formed by being cut from an extrusion material made of analuminum alloy or a magnesium alloy having a constant cross-sectionalshape in a direction orthogonal to the width direction.